Haemodynamic Effects of Four Sevoflurane Wash-In Strategies After Tracheal Intubation

The goal of this clinical trial is to compare how four different ways of starting sevoflurane anaesthesia (the \"wash-in\" phase) affect the heart and circulation during the first 10 minutes after endotracheal intubation in adults undergoing elective major urological surgery. The main question it aims to answer is whether the wash-in strategy affects cardiac index 10 minutes after intubation. Researchers also compared other haemodynamic variables, the time needed to reach the target anaesthetic concentration (0.8 MAC), sevoflurane consumption, the need for ephedrine to treat low blood pressure, and depth of anaesthesia. After a standard intravenous induction, participants were randomly assigned to one of four sevoflurane wash-in strategies: automated end-tidal-controlled delivery, or manual delivery with 0.5 L/min fresh gas flow and 8% sevoflurane, 1 L/min with 4% sevoflurane, or 2 L/min with 4% sevoflurane. Haemodynamic variables were measured continuously through a radial arterial line using the pressure recording analytical method (PRAM).